The present invention relates generally to aerodynamic lifting and control surfaces and control systems, and more particularly, to a wrapped grid fin and control system for use with aerodynamic vehicles such as missiles and torpedoes that may be folded around the vehicle for storage.
Conventional grid fins are disclosed in American Institute of Aeronautics and Astronautics paper AIAA 93-0035, entitled "Grid Fins--A New Concept for Missile Stability and Control," by W. D. Washington, U.S. Army Missile Command, Redstone Arsenal, Alabama. This paper was presented at the 31st Aerospace Sciences Meeting & Exhibit. Jan. 11-14, 1993. The disadvantage of the grid fins presented in this paper is that the arrangement of the internal grid precludes parallelogram folding and the corresponding use of flexible material for grid and box sides. Thus, this conventional grid fin arrangement is precluded from folding around the body of the missile and provide for a compressed storage configuration.
Conventional grid fin designs are configured to maximize strength to weight ratio by orienting the internal grid structure at 45.degree. to the main frae. This orientation results in a structure which can not be compressed in a radial direction, and must be stored by rotating the fin toward to the missile body in a plane defined by the deployed fin axis and the missile axis. The resulting external envelope required for the folded grid fins adds the fin chord length to the missile radius at each fin circumferential location. This additional storage volume makes the use of grid fins on airframes requiring compressed carriage unfeasible.
Accordingly, it is an objective of the present invention to provide for an aerodynamic lifting and control surface comprising a wrapped grid fin for use with an aerodynamic vehicle. It is a further objective of the present invention to provide for a aerodynamic lifting and control surface that may be folded around the body of the vehicle to provide for a compact storage arrangement. It is another objective of the present invention to provide for control system for use with aerodynamic vehicles that employs the aerodynamic lifting and control surface.